Collapsible fuel tank



May 5, 1959 Filed M y 15, 1957 B. F. GRIMM COLLAPSIBLE FUEL TANK 2 Sheets-Sheet l INIVENTOR BI'ZJCQ F 61.

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ATTORNEY y 5,1959 BF. GRIMM v 2,884,978

COLLAPSIBLE FUEL TANK Filed May 15, 1957 2 Sheets-Sheet 2 INVENTOR B17168 I?(Er/1312171v ATTORNEY United 1 COLLAPSIBLE FUEL TANK Bruce F. Grimm, Natick, Mass., assignor to the United States of America as represented by the Secretary of the Army The invention described herein, if patented, may be manufactured and used by or for the Government for governmental purposes, without the payment to me of any royalty thereon.

This invention relates to collapsible tanks for fuel or other liquids, and has for one of its objects to provide a collapsible inner bladder, which will reduce losses of liquid from the tank by diffusion, leakage, and defective seams.

Another important object of the invention resides in the provision of means placed between the tank and its bladder which will reduce the possibility of puncturing the bladder to a minimum.

A further object of the invention consists in providing a tank with a bladder type of liner, which may be removed and repaired or replaced, without repairing or replacing the casing.

Another object of the invention is to provide a tank in which liquid fuel, oil, or other liquids may be stored in hot climates for relatively long periods with minimum liability of contamination.

Other objects and advantages of the invention will be apparent from the following description when taken in connection with the accompanying drawings, in which,

Fig. l is a side elevational view of the collapsible fuel tank, the bladder being shown in dotted lines.

Figs. 2 and 3 are enlarged fragmentary sectional views showing the bladder attached to the inlet-outlet nozzle and the fitting for the injection of flotation liquid.

Figs. 4 and 5 are enlarged fragmentary sectional views of the tank at relatively low ambient temperatures and containing different amounts of fuel or the like, and

Figs. 6 and 7 are similar views showing the tanks at relatively high ambient temperatures and containing different amounts of fuel or the like.

Referring to the drawings in greater detail and by reference numeral, the number 1 indicates the body of the novel fuel tank, comprising an outer tank or casing 2 and an inner bladder 3. The outer casing is preferably made of laminated flexible material, such as rubber-coated fabric, or a single layer of fabric of suflicient strength to support the contents. The bladder, on the other hand, may be made of extremely thin and flimsy material, such as Mylar polyester film described in brochures of E. I. du Pont de Nemours & Co., Inc., entitled Mylar Polyester Film Technical Report Properties TR-l, and Mylar Polyester Film Technical Report Adhesives TR-2, of the type described in E. I. du Pont de Nemours Patent No. 2,650,213, or other suitable materials.

The material of the casing 2 is provided with an opening 4 to which is attached in any suitable manner a rubber ring 5 in which is imbedded a metal insert 6. The bladder 3 is provided with a corresponding opening, and the material surrounding the opening is wrapped around the ring 5 as indicated by numeral 7. The free edge of the material 7 rests on top of the ring 5, and is reinforced by a ring of Mylar or other material 8 which may be atent O 2,884,978 Patented May 5, 1959 cemented or welded thereto or otherwise permanently connected. The structure thus far described provides an inlet-outlet opening 9 for the collapsible tank and a nozzle 10 is detachably mounted therein. This nozzle is provided with an annular flange 11 having a series of uniformly spaced apertures for receiving machine screws 12 which may be threaded into the metal insert 6. A sealing gasket 13 may be disposed between the flange 11 and the reinforced portion 8 of the liner 3, so as to insure the tank against leakage.

The nozzle 10 is provided with an inwardly directed portion 14 having a series of suction openings 15 spaced above the lower end thereof to prevent the entrance of dregs, as is customary. The outer end of the nozzle may be provided with an annular groove 16 of semi-circular cross-section to permit the use of the conventional camlocking Evertite fitting 17.

In order to interpose water or other fluent material, having a higher specific gravity than the fuel, between the bladder and the casing, the material forming the casing is provided with an opening 18 to which is attached, in any suitable manner, a rubber ring 19, having a metal insert 20, to provide an inlet opening 21. The inlet nozzle is indicated by the numeral 22 and is provided with an annular flange 23 having uniformly spaced apertures for the reception of machine screws 24 which are threaded into the metal insert 20. The outer end of the nozzle 22 is provided with an annular groove 25 of semicircular cross-section to permit the use of the conventional cam-locking Evertite fitting 26.

In Figs. 4 to 7, inclusive, the collapsible tank is illustrated under various conditions. For instance, Figure 4 shows the tank with a small charge of liquid fuel 27 in the bladder 3, and fluent material, such as water 28, disposed between the bladder 3 and the casing 2 having been placed therein by passage through the nozzle 22. The material 28 should always be one having a greater specific gravity than the liquid placed in the bladder 3, and, as will be noted in each of the four figures, the bladder and its contents will float upon or rest upon the material 28. In each of Figures 4 and 5, the tank is shown at low ambient temperature, but the tank of Figure 5 is charged with a much greater amount of the liquid 27 and consequently the bladder is distended to a greater extent than in Figure 4 and has displaced a substantial portion of the material 28 from the bottom of the tank up around the sides as indicated by the letter A.

The proportions of the liquid 27 shown in Figures 6 and 7 are the same as in Figures 4 and 5, but in these Figs. 6 and 7, the ambient temperature is relatively high and consequently the expansion of the vapors 29 within the tank has fully distended it in contrast to the partly collapsed upper portion shown in Figs. 4 and 5. The condition of the material 28, however, is substantially the same as that illustrated in Figs. 3 and 4, that is to say, the bladder 3 and its heavier charge has been forced downwardly in Figure 7 and consequently a substantial portion of the sustaining material 28 has been forced up around the sides of the bladder as indicated by the letter B.

By reason of the novel structure shown and described herein, it will be noted that loss of the contents of the bladder, i. e., the petroleum products, or other liquid, is greatly reduced, partly because of the absence of fabric in the bladder (as used in current practice) which permits wicking in the seams and partly because the double wall construction in which the walls are maintained in spacedapart relationship by a liquid having greater specific gravity than that carried in the bladder, will reduce the possibility of puncturing the bladder to a minimum. It will also be noted that due to the material of which the bladder is fabricated, it may be readily collapsed into 3 a fla'tively anaesafid Withdrawn through the inletotitlt' opening 9 fortne'pnrpcse'nfrepair or replacement if necessary.

In accordance with the patent laws I have described what is now considered to be the preferred form of the invention, but it is to be understood that various minor changes may be made instructiiral details without departing from the spirit of the invention, and it is intended that such changes be included within the scope of the appended claims.

I claim: I

1. A collapsible storage tank fof gasoline or the like comprising collapsible inner and outer containers of flexible material having registering openings, a rigid ring, means for securing the edges of the openings to said ring, said container being otherwise unconnected, a closure cooperating with the ring, said enter container provided with a second opening,- a closure for the latter opening, and

a charge of liquid between said cont'ainei's having a specific gravity greater than that of the gasoline or the like.

2. A collapsible storage tank for gasoline or the like comprising a collapsible outer casing of flexible material, a collapsible inner container or bladder formed of a polyester, and a charge of liquid between said containers having a specific gravity greater than that of the gasoline or the like.

References Cited in the file of this patent UNITED STATES PATENTS 1,351,395 Martinean Aug. 31, 1920 1,696,138 Day et a1. -1- Dec. 18, 1928 1,706,335 Toch Mar. 19, 1929 2,421,613 Gray et al. June 3, 1947 2,748,673 Winstead s June 5, 1956 2,751,953 Grimm June 26, 1956 2,776,691 Tupper Jan. 8, 1957 

1. A COLLAPSIBLE STORAGE TANK FOR GASOLINE OR THE LIKE COMPRISING COLLAPSIBLE INNER AND OUTER CONTAINERS OF FLEXIBLE MATERIAL HAVING REGISTERING OPENINGS, A RIGID RING, MEANS FOR SECURING THE EDGES OF THE OPENINGS TO SAID RING, SAID CONTAINER BEING OTHERWISE UNCONNECTED, A CLOSURE COOPERATING WITH THE RING, SAID OUTER CONTAINER PROVIDED WITH A SECOND OPENING, A CLOSURE FOR THE LATTER OPENING, AND A CHARGE OF LIQUID BETWEEN SAID CONTAINERS HAVING A SPECIFIC GRAVITY GREATER THAN THAT OF THE GASOLINE OR THE LIKE. 